500kV同塔双回蝶沧线潜供电弧参数计算与分析

Calculation and Analysis on Secondary Arc Parameters of 500 kV Dieling-Cangjiang Double-Circuit Line on the Same Tower

线路稳态下的潜供电弧参数(潜供电流和恢复电压)是其潜供电弧自灭的两个决定因素。推导了以分布参数法求解同塔双回线在发生单相接地故障时的潜供电弧参数的计算公式,考虑线路末端装设并联电抗器时对这些参数的影响。以500 kV同塔双回蝶沧线为例,计算其潜供电弧参数,以验证算法的正确性。分析显示,潜供电流与恢复电压不仅与线路参数有关,而且还与线路的电流(或输送潮流)及故障点位置密切相关;当线路无并联电抗器时潜供电流会增大,线路熄弧时间将延长。

The secondary arc parameters of a transmission line in a steady state, i.e. its secondary arc current and recovery voltage, are the key factors of its secondary arc being extinguished itself. This paper deduces the calculation formulae of secondary arc parameters for a double-circuit line in a single phase grounding failure, and discusses the impact of the case there being shunt reactor installed at the end of the line on the parameters. The 500 kV Dieling - Cangjiang double-circuit line on the same tower is taken as an example for secondary arc parameters calculation as to verify the correctness of the proposed algorithm. It proves that the sedondary arc parameters are related not only with the line parameters, but also with the line current （or power load）. The secondary arc current becomes larger if there is no shunt reactor, and thus the extinguishing time of the line arc becomes longer too.